Simulation of cosmic ray failures rates using semiempirical models

A method for the calculation of failure rates due to cosmic rays is presented. The method is based on the output of standard device simulation tools and is applied to IGBTs and free-wheeling diodes. Different models for the failure rate density are compared with respect to their consistency with experimental data. The method is applied both to the active area and to the edge termination of IGBTs. Furthermore the influence of gate voltage on the failure rate of IGBTs is investigated. The method can be used to predict failure rates over a wide range of voltage classes and to detect weak points of device design.